The present invention relates generally to compensated amplifiers, and more particularly to a compensated feedback amplifier having a voltage-controlled compensation circuit.
Shunt and series feedback amplifiers are forms of amplifiers in which a resistive element is connected from output to input to establish a precise gain factor. Such feedback amplifiers are used in a wide variety of applications so as to be pervasive in the electronics industry. It is also typical to provide capacitive compensation to achieve stability and optimum transient response or frequency response. This compensation is typically implemented by placing a variable capacitor in parallel with the feedback resistor to allow optimum compensation to be adjusted. One problem associated with variable capacitors is that they typically introduce significant parasitic capacitances and inductances into the circuit to be compensated, and consequently can be difficult to adjust for optimum transient response. Also, if the circuit involves more than one feedback capacitor, the problem is compounded. Moreover, it has been heretofore impractical to adjust feedback capacitance as a function of temperature or voltage.